1. Field of the Invention
The present invention relates to an immobilized enzyme which can advantageously be employed in the production of di-D-fructofuranose 2',1:2,3'-dianhydride, hereinafter referred to as "DFA III".
2. Description of the Prior Art
Inulin-D-fructotransferase (inulinase II), hereinafter abbreviated as "FTF", is an enzyme producing DFA III from inulin.
DFA III is a disaccharide having the structure in which two molecules of fructose are condensed with dehydration via 1,2'- and 2,3'-linkages, ad has been isolated and identified in 1931 by Jackson et al. Bur. stand. J. Res., 6, 709 (1931). DFA III may notably be regarded as a low-calorie sweetener since it is not metabolized nor fermented in animal bodies and is expected to be utilized in various applications, including use for a diet food, in the future.
Various bacteria which may produce FTF have been known and include, for example, Arthrobacter ureafaciens 7116 (FERM P-1969), Arthrobacter globiformis C11-1 (FERM P-8748), Arthrobacter aurescens IFO 12136 (Uchiyama et al., 1975, the 48th congress of the Society of Japan Biochemistry), and Pseudomonas fluorescens No. 949 (Kuramoto et al., the congress of the Society of Japan Agricultural Chemistry, p. 654 (1987) and p. 112 (1988)).
The present inventors have also found that Arthrobacter ilicis MCI-2297 (FERM P-9893, also designated as FERM BP-2279 under the Budapest Treaty) can also produce FTF Japanese Patent Application No. 53164/1988; Uchiyama et al., the congress of the Society of Japan Agricultural Chemistry, p. 296 (1988).
In conventional enzymic reactions utilizing such enzymes in aqueous solutions, modification or removal of the enzymes will be required in order to industrially collect desired products after reaction. Thus, the enzymes should be discarded every reaction even though they are still active, resulting in economical disadvantages.
If an attempt is made to recover the enzymes, then some treatment such as ultrafiltration will necessarily be done which requires a lot of equipments and time to separate the enzymes from the reaction mixture. Thus, this is also disadvantageous economically.